Planet 9

**CCC4321** · #1 10-26-2007, 10:47 AM

Here are my Dyno charts for my before and after with the bbiautosport

Under-Drive Pulley

**Slatfatf** · #2 10-26-2007, 12:07 PM

That's a very worthwhile gain! How hard was the installation? Did you do it yourself? Were any special tools involved? How is this underdrive pulley different from the one supplied by Mantis?

Thanks for the posting!

**CCC4321** · #3 10-26-2007, 12:42 PM

Originally Posted by Fort Felker

That's a very worthwhile gain! How hard was the installation? Did you do it yourself? Were any special tools involved? How is this underdrive pulley different from the one supplied by Mantis?

Thanks for the posting!

I had BBI install mine, but I know someone who has installed their own pulley. It needs a special tool that is included as well as the crank pulley bolt for about $250. Keeps the power-steering cooler and ads some HP.

**Slatfatf** · #4 10-26-2007, 02:31 PM

I think I'm gonna do the underdrive next. Now that some before/after dyno data has been posted, this seems like a good value in terms of $/HP, plus it eliminates the power steering problems reported by some trackers. I could save some $ if anybody has a pulley tool that I could borrow. And although I have a 32mm socket left over from my 911 days, I don't relish the hassle of grinding it down so it'll fit in the small space avaialable for the pulley nut. So does anybody have a ground-down 32mm socket I could borrow, and a pulley tool as well? I'm in Northern California and could pick-up and deliver, or I'd pay shipping otherwise.

Thanks in advance!
Fort Felker

**zornet** · #5 10-29-2007, 08:31 PM

Oh yes CCC4321 this is on my to-do list. There isn’t a better shop to have it installed at either; our zone 8 is a lucky zone for sure. Luckily others can also acquire his Under-Drive Pulley also directly from BBI (soon to be a sponsor!).

zornet

chaseman · #6 10-30-2007, 10:39 PM

Originally Posted by zornet

Oh yes CCC4321 this is on my to-do list. There isn’t a better shop to have it installed at either; our zone 8 is a lucky zone for sure. Luckily others can also acquire his Under-Drive Pulley also directly from BBI (soon to be a sponsor!).

zornet

Hey Z,
What are you waiting for? get it done. I had my installed from BBI last month. It is relatively cheap for the HP gain. You better get it done by the summer time if you are planning to track frequently.

Ciao,

Chaseman

Joe_Tule · #7 10-30-2007, 11:06 PM

I really can't read these. Can you render a simple explanation?

ThnaX!

**CCC4321** · #8 11-01-2007, 11:22 AM

Originally Posted by Joe_Tule

I really can't read these. Can you render a simple explanation?

ThnaX!

The under-drive pulley, under drives the accessories ( AC, Power steering , Alternator...) which in turn frees up HP/Torque. The original idea was to help the Power Steering from overheating malfunctioning by slowing down the pump, which has happened to many Caymans that have done DEs and AXs.

Kor · #9 11-01-2007, 01:15 PM

Have you tried seeing if your alternator can keep up? Fire up the HID's and crank up your BOSE system and turn on your windshield wipers, fogs, and interior lights. Any flickering?

Joe_Tule · #10 11-01-2007, 01:29 PM

Originally Posted by Kor

Have you tried seeing if your alternator can keep up? Fire up the HID's and crank up your BOSE system and turn on your windshield wipers, fogs, and interior lights. Any flickering?

Please let us know how much your lights dim, you wipers' speed slows and other possible untoward effects on your alternator!

Thank you in Advance

**CCC4321** · #11 11-01-2007, 04:22 PM

There is no flickering or dimming at all. I have been in the rain at night and there were no problems. I have used under-drive pulleys in the past on other cars as well with no issues. Hondas and Acuras

spindoc · #12 11-01-2007, 07:05 PM

Originally Posted by Kor

Have you tried seeing if your alternator can keep up? Fire up the HID's and crank up your BOSE system and turn on your windshield wipers, fogs, and interior lights. Any flickering?

No problems - using Mantis underdrive pulley.

**Andy (Portland, OR)** · #13 11-02-2007, 01:16 PM

Can someone please explain the difference, if any between the BBI and Mantissport under drive pulleys: design, cost, dyno.

Apologies if covered elsewhere -- couldn't find it.

Thanks, Andy

boinkus44 · #14 11-02-2007, 02:34 PM

Also using the Mantis underdrive pulley. No issues at all.

**CCC4321** · #15 11-02-2007, 07:14 PM

The BBI pulley is cheaper than the other. It comes with the install tool and crank bolt for $250, the other does not, and cost more.
I was told the BBI pulley is better balanced, and fits the belt better.
From what I have seen on my car the BBI made more HP than the other.
The BBI pulley has five equally spaced holes, where the other has two on one side so it makes sense to me that it is not balanced.

gtscayman · #16 11-02-2007, 10:47 PM

Originally Posted by CCC4321

I was told the BBI pulley is better balanced, and fits the belt better.
From what I have seen on my car the BBI made more HP than the other.
The BBI pulley has five equally spaced holes, where the other has two on one side so it makes sense to me that it is not balanced.

I don't think you can tell solely from where the holes are whether it is balanced or not. If I had to guess, the one with the two holes on one side would be the balanced one and not the one with five equally spaced holes (which would do nothing for balance, but would reduce weight - and it still might be balanced....)

**4by4** · #17 11-03-2007, 12:08 AM

Can any one direct me to details about the BBI under drive pulley? Nothing at their web site.
cheers.

**Slatfatf** · #18 11-03-2007, 01:16 AM

Originally Posted by 4by4

Can any one direct me to details about the BBI under drive pulley? Nothing at their web site.
cheers.

I've tried multiple emails and phone calls, and I can't get any response from them!!

**CCC4321** · #19 11-03-2007, 09:56 AM

Originally Posted by Fort Felker

I've tried multiple emails and phone calls, and I can't get any response from them!!

I believe everyone is at SEMA in Las Vegas.

**4by4** · #20 11-05-2007, 10:28 PM

I got some feedback.

The Pulley will come with a holding tool and the new crank bolt. The kits cost is $239.00. For some one who is mechanically inclined, It will take you about 2 hours. The pulley is under driven by 16% and retains the stock belt. On our dyno, we found 7 peek hp and up to 10 mid range hp.

All sounds good. Shall I order? That is the question now...